Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-08T08:30:01.021Z Has data issue: false hasContentIssue false
  • English
  • Français

Motukoreaite—additional data and comparison with related minerals

Published online by Cambridge University Press:  05 July 2018

G. W. Brindley
G. W. Brindley*
Affiliation:
126 Mineral Sciences Building, The Pennsylvania State University, University Park, PA 16802
Get access Rights & Permissions [Opens in a new window]

Summary

Motukoreaite resembles hydrotalcite and has positively charged brucite-like layers separated by carbonate and sulphate anions and water molecules. Four phases are recognized. Phase I, the normal mineral with an 11.1 Å basal spacing, readily changes to a mixture of phase I and a partially dehydrated phase II. Phase III with a basal spacing 8.7 Å persists from 50–170°C. Phase II is a pseudo-regular interstratification of phases I and III, with a spacing 11.1 + 8.7 = 19.8 Å; second- and third-order reflections are observed. Phase IV with a 7.5 Å spacing is obtained by treating motukoreaite with sodium carbonate solution to replace SO4 by CO3 anions. Motukoreaite itself shows only slight tendency to transform to a 7.5 Å phase by heat-treatment alone. Comparison is made with the mineral carrboydite, a NiAl sulphate carbonate hydrate. The possibility is considered that sulphate anions may substitute partially in the brucite-like layers to compensate for a deficiency of hydroxyl ions.

Type
Research Article
Information
Mineralogical Magazine , Volume 43 , Issue 327 , September 1979 , pp. 337 - 340
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1979

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bish, (D. L.), 1977. Ph.D. thesis, Pennsylvania State University.Google Scholar
Bish, (D. L.) 1978. Bull. du Bureau de Recherches Géologiques et Miniéres, Sect. II, Géologie des Gîtes Minéraux, No. 3, 293301.Google Scholar
Brindley, (G. W.) and Kikkawa, (S.), 1979. Paper in preparation for publication.Google Scholar
Gastuche, (M. C.), Brown, (G.), and Mortland, (M. M.), 1967. Clay Minerals. 7, 17 792.CrossRefGoogle Scholar
Nickel, (E. H.) and Clarke, (R. M.), I976. Am. Mineral. 61, 366 72.Google Scholar
Rodgers, (K. A.), Chisholm, (J. E.), Davis, (R. J.), and Nelson, (C. S.), 1977. Mineral. Mag. 41, 389-90 and M21-M23.CrossRefGoogle Scholar
Taylor, (H. F. W.), 1973. Ibid. 39, 377-89.Google Scholar